Gaia: accurately mapping location, motion, color & brightness of 1.7 billion stars in the Milky Way

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This is fascinating news towards accurately mapping all ~100 billions starts in the galaxy

This morning, the European Space Agency unveiled a new, highly detailed sky map of the Milky Way Galaxy that showcases the brightness and positions of nearly 1.7 billion stars. It’s the most comprehensive catalog of stars to date, and it includes precise details about many of the stars’ distances, movements, and colors as well. With the map’s release, astronomers are hoping to use this information to learn more about the structure of our galactic home and how it first formed billions of years ago.
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Plus, the Gaia data includes information about how fast some stars are moving toward us or away from us, in what is known as radial velocity. Astronomers were able to make this measurement for 7 million stars. “It’s a small number compared to the 1.7 billion, but it’s still the largest radial velocity survey ever conducted,”

The European team presented new images of our galaxy based on some initial analyses of the data, along with little movies that simulated what it would be like to fly through the stars. "It's not fake, it's real measurements," Brown said. "We know exactly where the stars are."

“It’s like waiting for Christmas,” said Vasily Belokurov, an astronomer at the University of Cambridge in the United Kingdom last week. Today, the gifts arrived: the exact positions, motions, brightnesses, and colors of 1.3 billion stars in and around the Milky Way, as tracked by the European Space Agency’s (ESA’s) €750 million Gaia satellite, which after launch in 2013 began measuring the positions of stars and, over time, how they move. On 25 April, ESA made Gaia’s second data set—based on 22 months of observations—publicly available, which should enable a precise 3D map of large portions of the galaxy and the way it moves. “Nothing comes close to what Gaia will release,” Belokurov says.

With these accurate measurements it is possible to separate the parallax of stars – an apparent shift on the sky caused by Earth’s yearly orbit around the Sun – from their true movements through the Galaxy.

https://www.esa.int/Our_Activities/...tes_richest_star_map_of_our_Galaxy_and_beyond

https://www.theverge.com/2018/4/25/...-milky-way-galaxy-stars-european-space-agency
https://www.npr.org/sections/thetwo...veil-precise-map-of-more-than-a-billion-stars
http://www.sciencemag.org/news/2018...ions-more-1-billion-stars-and-shape-milky-way